CHAPEL HILL, N.C. (AP) -- Xylina McDaniel had a perfectly good explanation for a taking a shot while seated on the floor under the basket.
''I was just so wide open, I guess,'' she said with a laugh.
McDaniel made that shot down the stretch and then added a put back off an offensive rebound with 56 seconds left to put North Carolina ahead for good, helping the fourth-seeded Tar Heels overcome an 18-point second half deficit and defeat UT Martin 60-58 on Sunday.
She finished with 14 points, helping UNC advance to a second-round matchup with No. 5 Michigan State on Tuesday.
UT Martin was looking to become only the seventh No. 13 seed ever to pull an upset in the first-round.
And for a while it looked like they would.
The Skyhawks led 50-32 with 10:51 left in the game when Diamond DeShields ignited a 15-0 run after making two free throws after taking an elbow to the throat, which drew a flagrant foul. DeShields, the conference's freshman player of the year, had 13 of her 15 points during the second half.
DeShields said the flagrant foul ''ignited a match'' under the sleeping Tar Heels.
''Everybody just collectively decided we didn't want our season to end, especially like that on our home court,'' DeShields said. ''With time running down we had like 10 minutes to continue our season. I wasn't ready to stop playing.''
Said UNC assistant coach Andrew Calder: ''Just the will and the want to play for each other carried us through.''
Karisma Tyson had a chance to win the game for UT Martin but her 3-pointer at the buzzer was off the mark.
Heather Butler finished with 19 points for UT Martin, tying the all-time NCAA career record for career 3-pointers made. Butler finished her career with 392 3s, tying the mark set by Kansas State's Laurie Koehn in 2005.
UT Martin seemed to surprise the taller Tar Heels with their speed and ability to get to the basket in the early going.
Led by Butler, who had 13 points at the break, the Skyhawks were 6 of 13 from 3-point range in the first half and built a 35-22 lead at the break. UNC was just 1 of 10 from 3-point range in the first half.
Using a triangle-and-two defense on DeShields and McDaniel, the Skyhawks frustrated the Tar Heels in the first half. UT Martin held DeShields was 0 for 4 from the field before the break.
UT Martin coach Kevin McMcMillan called it ''crazy idea'' that almost worked.
But in the end, UNC moved on to the next round.
Leading 54-53 with three minutes to go, McDaniel turned in the play of the game.
She wound up on the floor going for an offensive rebound and the ball fell into her lap. She looked around momentarily and then threw the ball off the glass and into the basket. McDaniel smiled and laughed as she got up and ran back down the floor.
''I was thinking you can't make a shot standing up right at the basket and then you make the one sitting on the ground,'' Calder said. ''That was kind of the way it was going tonight.''
UT Martin wasn't done though.
Jasmine Newsome knocked down a 3-point with 1:15 left in the game to tie it at 58.
But when Latifah Coleman missed a jump shot, McDaniel was there for the put back and the go ahead points, helping salvage UNC's season.
The game was delayed at the start of the second half because the scoreboard at Carmichael Arena had to be lowered to the floor to fix a buzzing noise in the sound system. It took about 15 minutes to fix the problem.
The delay didn't seem to bother UT Martin.
They stayed hot in the second half working the ball inside to Ashia Jones, who seemed to score at will in the low post. She finished with 18 points and eight rebounds.
Afterward, UT Martin's players were left wondering what could have been.
''We fought, we fought, and it's just really hard to lose that ball game when I know we deserved it, you know,'' Butler said. ''We deserved it. We fought so hard and just had it in our hands and there it went. It hurts and it's going to hurt probably for the rest of my life but you know that's the way it goes sometimes.''
After the game, fans were briefly forced to stay inside Carmichael Arena after police announced there was an armed and dangerous person near the campus. The suspect was later captured and the alert was called off and fans were allowed to leave.